Interstingly this could make sense, because they're selling off all of the Yahoo! assets there is no reason there is no incentive to use Yahoo! mail and in fact they lose the rights to those assets once the sale is completed.

Altaba will still be holding all of the other assets not sold to verizon so this is likely the best way to move forward for whoever is left working for this not quite dead entity once the sale is complete.

Suppose they'll be less likely to get hacked.

Haha. Thanks for the chuckle.

Maybe I could be hitting a cache or something, but here's what I see:

  $ host Altaba.com
  Altaba.com mail is handled by 10 alt4.aspmx.l.google.com.
  Altaba.com mail is handled by 1 aspmx.l.google.com.
  Altaba.com mail is handled by 5 alt1.aspmx.l.google.com.
  Altaba.com mail is handled by 5 alt2.aspmx.l.google.com.
  Altaba.com mail is handled by 10 alt3.aspmx.l.google.com.

Here's yahoo.com for reference:

  $ host yahoo.com
  yahoo.com has address 206.190.36.45
  yahoo.com has address 98.138.253.109
  yahoo.com has address 98.139.183.24
  yahoo.com has IPv6 address 2001:4998:58:c02::a9
  yahoo.com has IPv6 address 2001:4998:c:a06::2:4008
  yahoo.com has IPv6 address 2001:4998:44:204::a7
  yahoo.com mail is handled by 1 mta7.am0.yahoodns.net.
  yahoo.com mail is handled by 1 mta5.am0.yahoodns.net.
  yahoo.com mail is handled by 1 mta6.am0.yahoodns.net.

And that's not everything because this is the TXT record

altaba.com. 1800 IN TXT "google-site-verification=vO3De5z6qb-AeM1GmHkcC5dlWA_cw-7WKN5xhcyFFPM"

That's required for Google's domain ownership verification, which is a pre-requisite to enabling G Suite (formerly known as Google Apps for Domains).